Racing will resume at Newbury on Friday, six days after the death of two horses by electrocution before the start of the first race on Totesport Trophy day. That race remains the feature event of the rescheduled card, with 15 runners due to go to post, but while there will be few obvious signs at the track of the drama that played out on Saturday it could be several weeks before every question about the tragic accident is answered as fully as possible.

Southern Electric, which removed a cable from the paddock area for examination earlier this week, stressed on Thursday that its investigation into the incident is "still ongoing", but the track has satisfied that British Horseracing Authority that it is completely safe for both humans and horses.

"Now that we've been given the all-clear, it's important to get back to business, and important to support the horsemen in what's been a difficult winter already," Stephen Higgins, Newbury's managing director, said. "We are a racecourse, and we need to get on with racing.

"The construction of the cable is going to be examined in great detail and hopefully SE will be able to provide us with a reason why it broke down, as obviously we are as interested as anybody. We need to give them time to get it right, and we will await their full report. It would be unfair to put pressure on them to rush it through."

Incidents such as the one on Saturday are extremely rare and the BHA has found only two previous examples involving racehorses worldwide.

"The cable was feeding a redundant building, that's really as much as we know at this stage," Higgins said. "It was on their [SE's] network, and it was their responsibility."

Today's card will not carry the same level of prize money as the original meeting, but it will be televised live on Channel 4, and has attracted 59 declared runners across seven races.

"It is expensive to restage a meeting like this and the values are down," Higgins said, "but the crowd and the hospitality business on a Saturday is very different to what we can expect on a Friday, when there will be a much smaller crowd on the ground and no hospitality. It's a different model altogether."

The results of post-mortem examinations on Fenix Two and Marching Song, the two horses who died on Saturday, have confirmed that both were electrocuted. "The authority has been officially informed that there was leakage of electricity from a cable under the parade ring in the area where the incident occurred", Tim Morris, the British Horseracing Authority's director of equine science and welfare, said.

"There was immediate veterinary attention, and our inquiry on the day noted the racecourse veterinary surgeons felt a tingling sensation when examining the horses, and that the veterinary surgeons noted particular clinical signs such as muscle contractions.

"Both horses … have undergone examinations which showed sudden cardiac arrest as the cause of death. Samples taken from the horses affected have shown no evidence of substances that could have caused this incident. These findings are all consistent with the cause of death being accidental electrocution and at this stage we are not investigating any other cause of death.

"I can also confirm that, contrary to speculation, no evidence of any burn marks around the mouth was found on post-mortem examination, neither were such marks found by the veterinary surgeons on the horses at the start."